The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 17, 2019
Filed:
Nov. 29, 2017
Semiconductor Energy Laboratory Co., Ltd., Kanagawa-ken, JP;
Ryohei Yamaoka, Kanagawa, JP;
Satoshi Seo, Kanagawa, JP;
Shogo Uesaka, Kanagawa, JP;
Shiho Nomura, Kanagawa, JP;
Abstract
A highly reliable light-emitting element which can keep favorable characteristics throughout long-time driving is provided. In addition, a light-emitting element with high color purity and high emission efficiency is provided. Furthermore, a light-emitting device having a long lifetime in which the light-emitting element is used is provided. Moreover, an electronic device and a lighting device each of which has a long lifetime are provided. In the light-emitting element including an EL layer between a pair of electrodes, the EL layer has a stacked-layer structure of a first light-emitting layer, a second light-emitting layer, and a third light-emitting layer. The light-emitting layer includes an electron-transport material, a hole-transport material, and a light-emitting material. Furthermore, light emitted from the first light-emitting layer and light emitted from the third light-emitting layer have the same color and each have a longer wavelength than light emitted from the second light-emitting layer.